Mara-db

- add entry point `mara.commands` (for [mara-cli](https://github.com/mara/mara-cli) support)

- add cli group 'mara-db'. Mark old cli commands as deprecated (74)

Bugfixes :bug:

- fix typo in depreciation warn messages and add warn category
- fix JSONL data import into PostgreSQL db (73)

- hotfix :bug: issue with postgres cursor context (72)

Breaking Changes

- the implementation of the formats option (56) required to do changes to the functions in `mara_db.shell`. In case you defined custom implementations, you will have to adjust them.

Feat :tada:

- adding a functional API to get the DB-API 2.0 of a database (71)
- add option to specify multiple formats like Parquet, Avro and ORC (56, 64)

Changes :rocket:
- refactor the internally used cursor context logic to a more generic one (68, 71)
- a default database `mara` is not anymore defined (67).
- add deprecation warning when using parameter `timestamp` in query_command. This parameter will be removed in version 5.0. See 44.

Bugfixes :bug:

- fix sqlalchemy_url for SQLServerDB
- fix UI error when requesting schema view for Azure Synapse databases (48)

Breaking Changes

- when using BigQuery you need to rename the BigQueryDB db config parameter `service_account_private_key_file` to `service_account_json_file_name` (45)
- when using BigQuery with copy/read operations you need to specify parameter `gcloud_gcs_bucket_name` in the BigQueryDB db config (45)

Feat :tada:

- Add Databricks db support (62)
- Add Snowflake db support (52/61)
- Add sqlalchemy support for BigQuery (45/50)
- Add sqlalchemy support for SQL Server (46)
- Add option to use either MSSQL Tools (sqlcmd/bcp) or sqsh to connect to SQL Server (57)
- Add documentation readthedocs.io documentation (59)

Changes :rocket:
- Extend BigQuery functionality (45)
- add extras per database engine (50/53). Postgres and Readshift is still included by default. <br/>**Note:** It is recommended to always specifcy the extras for the database you use.
- use client-side rendering for graphviz fallback (51)

Bugfixes :bug:
- add all package files in wheel
- a proper error is now thrown when the user tries to look at the schema of a BigQuery database